This invention relates to aqueous oxidative, hair coloring compositions, which produce a vivid, intense dyeout having superior wash fastness and high resistance to light fading.
Modern hair dyeing methodology has developed from its initiation in the 1950""s to the point where, following shampoos and conditioners, today it is the third largest product type in the hair care category.
The most commonly used method of dyeing hair, particularly human hair, is oxidative dyeing in which a mixture of essentially colorless aromatic compounds, generally diaminobenzenes, dihydroxy benzenes and aminophenols, are converted by chemical reactions, that are well known to those skilled in the art, to a blend of colored compounds within the hair fibers. Shortly before use, the colorless aromatic compounds, in a suitable base formulation, are normally mixed with hydrogen peroxide or other strong oxidizing agents. The colored compounds or dyes are typically formed by oxidative coupling between primary intermediates (usually p-phenylenediamines or p-aminophenols) and couplers which are phenols, resorcinols, m-aminophenols or related cyclic compounds. Various shades are developed by using mixtures containing more than one of both the intermediate and the coupler.
Because of their low molecular weights and water solubility the primary intermediates and couplers diffuse easily into the hair where the coupling reaction takes place. The colored products developed by oxidation remain trapped in the hair because of their higher molecular weights, relative insolubility in water and absorptive affinity to the internal hair surface. This is the basis for permanent tints and toners which ideally last for the life of the hair and are relatively unaffected by light, shampooing and perspiration.
The practice of oxidative hair coloring is well known. Typically, it involves the use of a two-part system. One part, the dye component, contains at least one primary intermediate and at least one coupler. Before use, the dye component is mixed with a second part, which is a developer formulation containing an oxidizing agent. The developer oxidizes the primary intermediate to a quinone imine. This, in turn, reacts with a coupler to form a colored compound.
There are a number of primary intermediates and couplers that are used in the practice of oxidative dyeing of hair. Based on their frequency of use, the most useful primary intermediates, are the following: p-phenylenediamine, p-toluenediamine, p-amino-phenol, 2-chloro-p-phenylenediamine and 2-methoxy-p-phenylene-diamine. The most useful couplers, based on their frequency of use, are the following: resorcinol, 1-napthol, 2-methyl-resorcinol, m-aminophenol, 2,4-diaminophenolethanol, 5-methyl-3-aminophenol, 4-methyl-3-aminophenol and m-phenylenediamine. Many combinations of primary intermediates and couplers are known and described. The following United States patents contain some representative examples:
Although hydrogen peroxide is the most widely employed oxidant, other oxidizing agents are known and sometimes used. These include alkali and alkaline earth metal chlorites, which are described in U.S. Pat. No. 5,032,138. Other oxidizing agents employed in oxidative hair coloring include urea peroxide, melamine peroxide and perborates and percarbonates such as sodium perborate and sodium percarbonate.
All of the above-identified patents are incorporated herein by reference in their entirety.
To be useful for coloring hair; oxidative dye formulations should meet at least the following conditions:
1. They must provide a range of color shades that are acceptable to practitioners of hair coloring.
2. The couplers and primary intermediates must be properly dispersed to ensure that they rapidly penetrate into the hair.
3. The dye component should have the necessary properties so that when it is mixed with the developer, the resulting mixture has the desired rheological properties. The mixture preferably is thin enough to be able to spread onto the hair, but thick enough to stay in place during the color development period. If thickened, the mixture should also be readily rinsable from the hair with water.
4. The formulations should not be irritating to the scalp.
In order to meet conditions 2 and 3 above, mixtures of surfactants, organic solvents and thickeners, are included in all commercial hair dye preparations. Typical surfactants that are used in hair color formulations are nonoxynol-2, nonoxynol-4, nonoxynol-9, octoxynbl-1, laureth-4, laureth-23, oleth-4, oleth-21, sodium lauryl sulfate, sodium lauryl ether sulfate, sodium dodecyl benzene sulfonate, sodium cocamido propylbetaine, soyatrimmonium chloride, cetyl trimmonium chloride and behenyltrimmonium chloride.
Typical organic solvents used in hair color formulations include ethyl alcohol, isopropyl alcohol, carbitol, propylene glycol and hexylene glycol.
Typical thickeners used in hair color formulations include the surfactants described above, lauric acid diethanolamide, cocamide DEA and polyacrylic acid derivatives.